Find the charging port. In case your disposable vape is rechargeable, it must have a port which you could plug a charging cable into. This is normally a micro-USB or USB Form-C port on the base from the pen. You may want to use alligator clips to attach the wires. https://spencerdbtgp.blogkoo.com/not-known-factual-statements-about-rechargeable-disposable-vape-pen-58809712